1. Field of Invention
The present invention generally relates to lightweight self-healing composites comprised of region-specific microstructures and methods for their manufacture and, in particular, to lightweight self-healing composites which used in anti-ballistic applications.
2. Background of the Invention
The drive towards designing the “high-tech” solider and combat vehicle is fueling development of new material technologies that rival the revolution in materials seen during World War II, when the modern plastics industry was created. The primary function of anti-ballistic armor is to impede projectile penetration and to quickly diffuse the impact energy. To date anti-ballistic materials are primarily made from steel, high strength woven fibers including Spectra®, Kevlar®, Innegra-S® and Dyneema®, and ceramics of differing compositions.
In most cases, except for anti-ballistic steel, these commercially available products are woven, or in the case of Dyneema®, non-woven, in various configurations. Fibers are usually combined with other substrates, different in composition, to produce the final anti-ballistic material. The final products produced are composites of layers of anti-ballistic fabrics and substrates. These substrates include ceramic, steel, fiberglass, and in some cases thermoplastic materials as well as fiber cement board. Fabrics alone are not used as armor in high impact ballistic scenarios. Anti-ballistic steel is heavy and difficult to form, although it can be monolithic in form, not requiring secondary substrate layers. Some forms fuse two different types of steel of differing hardness as taught in U.S. Pat. No. 7,520,205, in any case they add to the armor's weight.
Ceramics are brittle in general and tend to degrade with multiple ballistic impacts requiring substrates to add to their integrity. Some are incased in thermoplastics or thermoset polymers to keep fragments of ceramic materials contained. Typical examples are described in U.S. Pat. No. 6,216,579, U.S. Pat. No. 6,389,594, and U.S. Pat. No. 7,603,939.
All current anti-ballistic materials are expensive and in most cases heavy. It is believed what is needed is a monolithic composite material that is easily formed, does not degrade under repeated fire, and is inexpensive to produce.